Oral immunization of pigs against classical swine fever. Course of thedisease and virus transmission after simultaneous vaccination andinfection

摘要

The efficacy of simultaneous vaccination of pigs against classical swine fever (CSF) and challenge was evaluated. In this study, domestic weanling pigs were vaccinated orally with a conventional live virus vaccine based on CSF virus (CSFV) C strain and were challenged simultaneously with CSFV of different virulence. All the animals vaccinated and challenged with a high dose of highly virulent Koslov strain died while three of five animals challenged with a low dose of highly virulent Alfort 187 strain survived shed the virus in nasal secretions, developed antibodies, and four of them showed a transient viremia. All the animals vaccinated and challenged with the low virulent field isolate MV 140/Riems survived showed a short viremia and developed antibodies. No CSFV or CSFV RNA could be detected in the animals surviving the infection. This study demonstrates that oral vaccination of wild boars in an infected area bears no risk for the development of a Persistent CSF infection.